A cable holding structure includes a shielded cable that includes a center conductor and a shield conductor on an outer periphery of the center conductor, and a holding portion being electrically conductive, provided on a flat plate portion and configured to hold the shielded cable. The holding portion includes a through-hole aligned in a direction intersecting with the flat plate portion. The shielded cable is held by the holding portion such that at least the center conductor is enclosed in the through-hole and the shield conductor is electrically connected to the conductive holding portion.